Abstract

Queensland has a public road network of 175, 000Km that is made up of both flexible and
rigid pavement types. These pavements are usually designed for a life expectancy of
approximately 20 years; however, the presence of poor subgrades can influence both the
durability and life of these pavements. Investigations of lime stabilised black soil in Dalby, Queensland were carried out to
determine the effects of delayed testing and to determine if Hilf Density Testing is a viable
method for inclusion in future Queensland Main Roads specifications. Both Dry Density
Testing and Hilf Density Testing were carried out over a 48 hour period. In addition to
density testing investigations, the main aim of the project was to find whether there was a
strength gain relationship for lime stabilised black soils.